They need to set up a long term experiment to see if sea plankton can survive in space indefinitely. If they can, that may be evidence to support the theory that life hitched a ride on an asteroid which crashed into Earth and life spread from there. The fact it is sea plankton is astonishing.
Didn't they already discover this with Tardigrades? An organism that can functionally endure radiation, vacuum, and temperature extremes the likes of which mean that hitching a ride on comets is an absolutely plausible way for life to travel throughout the solar system.
The plankton is, in my estimation, less interesting. They have hardened outer surfaces, produce energy through photosynthesis, and have proven to be significantly less complex than a Tardigrade. That kind of simplicity almost singularly produces a very survivable animal.
There are only two major scientific theories of how life came to be on Earth:
1) It evolved here from inorganic material.
2) It came here from elsewhere via an extraterrestrial body.
#1 should be testable in a lab but no tests have yielded positive results thus far (at least not any that are clearly capable of evolution). This discovery is evidence for #2.
Your conclusions seem, flawed.
I can agree with points 1 and 2, because the only option for 3 is beyond any provable reason. The conclusion that #1 is provable in a lab is pretty unrealistic. Have you ever been in a lab that has a planetary quantity of material to work with, or that can reproduce an early-earth environment with a planetary quantity of material?
If one exists I'm unaware of it. Creationists use the same logic to say that because it's "infinitely" unlikely that god did it.
The science, at this point, can demonstrate the rise of organic matter from non-organic matter. It can demonstrate that creatures can survive nearly indefinitely in space (even if they're not complex). As yet, both conclusions for the origin of life on Earth are equally valid and equally based on conjecture.
A science teacher put it to me like this. Your average UPS driver could make 30 stops in a day. This means that if he randomly chose his route each day, he could run that route every day of his life without ever having to run the same route twice (30! is huge). Despite this, I get my package from him every day between 2:00 and 2:15. The reality is that some unseen logic governs the action of the UPS delivery system. If I got all 30 stops on his route together I could conjecture as to how the route is planned, and even theorize as to how the planner determines his route. Humanity is doing the same thing with Physics and Chemistry. We may not know all of the laws, but we've got a solid theoretical framework that reasonably predicts the outcome. Until we observe the route planner in action, we can be proven incorrect rather easily.
